Individual Cathodoluminescence and Photoluminescence Spectroscopy of Zinc Oxide Nanoparticles in Combination with In Situ Transmission Electron Microscopy

2011 ◽  
Vol 11 (4) ◽  
pp. 3278-3283 ◽  
Author(s):  
Tokushi Kizuka ◽  
Masaya Oyama
2020 ◽  
Vol 16 (2) ◽  
pp. 137-152
Author(s):  
Mariana Buşilă ◽  
Aurel Tăbăcaru ◽  
Viorica Muşsat ◽  
Bogdan Ştefan Vasile ◽  
Ionela Andreea Neaşu ◽  
...  

Surface modification of zinc oxide nanoparticles (ZnO NPs) is a strategy to tune their biocompatibility. Herein we report on the synthesis of a series of fluorescent ZnO NPs modified with 2–10% (3-glycidyloxypropyl)trimethoxysilane (GPTMS) to investigate the fluorescence properties and to explore their applications in microbiology and biomedicine. The obtained ZnO NPs were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR). Size reduction occurred from ca. 13 nm in unmodified ZnO to 3–4 nm in silane-modified samples and fluorescence spectra showed size-dependent variation of the photoemission bands' intensity. The antibacterial and cytotoxic activities were investigated on Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria, and in ovarian (A2780) and prostate (PC3) cancer cells by tetrazolium/formazan-based methods. The antibacterial effect was higher for E. coli than S. aureus, while the cytotoxic activity was similar for both cancer cells and varied with the particle size. Cell death by apoptosis, and/or necrosis versus autophagy, were explored by flow cytometry using an Annexin V based-method and transmission electron microscopy (TEM). The main mechanism of ZnO NPs toxicity may involve the generation of reactive oxygen species (ROS) and the induction of apoptosis or autophagy. This work revealed the potential utility of GPTMS-modified ZnO NPs in the treatment of bacterial infection and cancer.


2016 ◽  
Vol 33 (1) ◽  
pp. 92-113 ◽  
Author(s):  
Sajad Shojai Nasab ◽  
Saeed Zahmatkesh

In this study, a new diacid monomer containing amide, imide, and sulfone functional groups was successfully used to synthesize a new poly(ether-amide) for membrane-based gas separation applications. The synthesized poly(ether-amide) was soluble in organic solvents, has high thermal stability (up to 460℃ under nitrogen atmosphere, for 10% weight loss), and high glass transition temperature (Tg = 274℃). This poly(ether-amide) was combined with different amounts of surface-modified zinc oxide nanoparticles to provide organic–inorganic nanocomposites. The optically transparent and flexible membranes of these hybrid nanocomposites were prepared. The obtained materials were characterized by Fourier transform-infrared spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, X-ray powder diffraction, field emission-scanning electron microscopy, and transmission electron microscopy techniques. Transmission electron microscopy of the nanocomposite film with 15 wt% zinc oxide confirms that the nanoparticles are well dispersed in the polymer matrix. Thermal gravimetric analysis data indicated that the hybrid materials had better thermal behavior with increasing surface-modified zinc oxide nanoparticles nanoparticle content. The poly(ether-amide)/surface-modified zinc oxide nanoparticles nanocomposite film mechanical properties improved with increasing surface-modified zinc oxide nanoparticles content. The permeability and selectivity of the poly(ether-amide)/zinc oxide membranes as a function of the surface-modified zinc oxide nanoparticles weight percentage were studied, and the results indicated that the CO2 and CH4 permeability increased with increasing zinc oxide content. In general, the membranes prepared from these polymers showed very good permeability and permselectivity for a pair of gases.


2004 ◽  
Vol 449-452 ◽  
pp. 1133-1136 ◽  
Author(s):  
Dong Un Seo ◽  
Cheng Zhu Lu ◽  
Ho Jung Chang ◽  
Sang Woo Joo

We examined quenching of growth of ZnO nanoparticles with the injection of various organic surfactants. Aliphatic isocyanides as well as organothiols were found to adsorb on ZnO nanoparticle surfaces. For a carboxylate-terminated thiol, a retardation of growth appeared to be effective presumably due to the adsorption of the carboxylate COO- group on the ZnO surface. Photoluminescence spectra and transmission electron microscopy images were obtained for thiolcapped ZnO nanoparticles. The thiol-capped ZnO nanoparticles was found to fluoresce at the wavelength shorter by ~6 nm than those in the absence of any organic surfactants.


Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 38 ◽  
Author(s):  
Banzeer Ahsan Abbasi ◽  
Javed Iqbal ◽  
Riaz Ahmad ◽  
Layiq Zia ◽  
Sobia Kanwal ◽  
...  

This study attempts to obtain and test the bioactivities of leaf extracts from a medicinal plant, Geranium wallichianum (GW), when conjugated with zinc oxide nanoparticles (ZnONPs). The integrity of leaf extract-conjugated ZnONPs (GW-ZnONPs) was confirmed using various techniques, including Ultraviolet–visible spectroscopy, X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, energy-dispersive spectra (EDS), scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The size of ZnONPs was approximately 18 nm, which was determined by TEM analysis. Additionally, the energy-dispersive spectra (EDS) revealed that NPs have zinc in its pure form. Bioactivities of GW-ZnONPs including antimicrobial potentials, cytotoxicity, antioxidative capacities, inhibition potentials against α-amylase, and protein kinases, as well as biocompatibility were intensively tested and confirmed. Altogether, the results revealed that GW-ZnONPs are non-toxic, biocompatible, and have considerable potential in biological applications.


2009 ◽  
Vol 08 (03) ◽  
pp. 277-279 ◽  
Author(s):  
MOHSEN OFTADEH ◽  
MASOUD SALAVATI-NIASARI ◽  
FATEMEH DAVAR

Zinc oxide nanoparticles were successfully prepared through the decomposition of zinc acetylacetonate precursor in oleylamine in the presence of triphenylphosphine. The products were characterized by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy.


2006 ◽  
Vol 05 (06) ◽  
pp. 951-958 ◽  
Author(s):  
XUEDONG BAI ◽  
EN GE WANG ◽  
ZHONG LIN WANG

Zinc oxide nanobelts, grown by a solid–vapor phase thermal sublimation process, are stimulating extensive interest because of their semiconducting and piezoelectric properties, diverse functionalities and chemical stability. For nanomanipulation and nanomeasurement of an individual ZnO nanobelts, in situ transmission electron microscopy (TEM) technique is a unique approach. In this paper, mechanical resonance of a single ZnO nanobelt, induced by an alternative electric field, was studied by in situ TEM. Due to the rectangular cross-section of the nanobelt, two fundamental resonance modes have been observed in corresponding to two orthogonal transverse vibration directions, showing the versatile applications of nanobelts as nanocantilevers and nanoresonators. The bending modulus of the ZnO nanobelts was measured to be ~ 52 GPa and the damping time constant of the resonance in vacuum of 10–8 Torr was ~ 1.2 ms. The ZnO nanobelts are promising in potential applications as nanocantilevers, nanoresonators and nanoactuators.


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